3 // Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the terms
7 // of the GNU General Public License as published by the Free Software
8 // Foundation; either version 3, or (at your option) any later
11 // This library is distributed in the hope that it will be useful, but
12 // WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 // General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file parallel/base.h
26 * @brief Sequential helper functions.
27 * This file is a GNU parallel extension to the Standard C++ Library.
30 // Written by Johannes Singler.
32 #ifndef _GLIBCXX_PARALLEL_BASE_H
33 #define _GLIBCXX_PARALLEL_BASE_H 1
37 #include <parallel/features.h>
38 #include <parallel/basic_iterator.h>
39 #include <parallel/parallel.h>
42 // Parallel mode namespaces.
45 * @namespace std::__parallel
46 * @brief GNU parallel code, replaces standard behavior with parallel behavior.
50 namespace __parallel
{ }
54 * @namespace __gnu_parallel
55 * @brief GNU parallel code for public use.
57 namespace __gnu_parallel
59 // Import all the parallel versions of components in namespace std.
60 using namespace std::__parallel
;
64 * @namespace __gnu_sequential
65 * @brief GNU sequential classes for public use.
67 namespace __gnu_sequential
69 // Import whatever is the serial version.
70 #ifdef _GLIBCXX_PARALLEL
71 using namespace std::__norm
;
78 namespace __gnu_parallel
80 // NB: Including this file cannot produce (unresolved) symbols from
81 // the OpenMP runtime unless the parallel mode is actually invoked
82 // and active, which imples that the OpenMP runtime is actually
83 // going to be linked in.
87 int __i
= omp_get_max_threads();
88 return __i
> 1 ? __i
: 1;
93 is_parallel(const _Parallelism __p
) { return __p
!= sequential
; }
96 // XXX remove std::duplicates from here if possible,
97 // XXX but keep minimal dependencies.
99 /** @brief Calculates the rounded-down logarithm of @c n for base 2.
101 * @return Returns 0 for any argument <1.
103 template<typename Size
>
108 for (k
= 0; n
> 1; n
>>= 1)
113 /** @brief Encode two integers into one __gnu_parallel::lcas_t.
114 * @param a First integer, to be encoded in the most-significant @c
115 * lcas_t_bits/2 bits.
116 * @param b Second integer, to be encoded in the least-significant
117 * @c lcas_t_bits/2 bits.
118 * @return __gnu_parallel::lcas_t value encoding @c a and @c b.
122 encode2(int a
, int b
) //must all be non-negative, actually
124 return (((lcas_t
)a
) << (lcas_t_bits
/ 2)) | (((lcas_t
)b
) << 0);
127 /** @brief Decode two integers from one __gnu_parallel::lcas_t.
128 * @param x __gnu_parallel::lcas_t to decode integers from.
129 * @param a First integer, to be decoded from the most-significant
130 * @c lcas_t_bits/2 bits of @c x.
131 * @param b Second integer, to be encoded in the least-significant
132 * @c lcas_t_bits/2 bits of @c x.
136 decode2(lcas_t x
, int& a
, int& b
)
138 a
= (int)((x
>> (lcas_t_bits
/ 2)) & lcas_t_mask
);
139 b
= (int)((x
>> 0 ) & lcas_t_mask
);
142 /** @brief Equivalent to std::min. */
145 min(const T
& a
, const T
& b
)
146 { return (a
< b
) ? a
: b
; }
148 /** @brief Equivalent to std::max. */
151 max(const T
& a
, const T
& b
)
152 { return (a
> b
) ? a
: b
; }
154 /** @brief Constructs predicate for equality from strict weak
157 // XXX comparator at the end, as per others
158 template<typename Comparator
, typename T1
, typename T2
>
159 class equal_from_less
: public std::binary_function
<T1
, T2
, bool>
165 equal_from_less(Comparator
& _comp
) : comp(_comp
) { }
167 bool operator()(const T1
& a
, const T2
& b
)
169 return !comp(a
, b
) && !comp(b
, a
);
174 /** @brief Similar to std::binder1st,
175 * but giving the argument types explicitly. */
176 template<typename _Predicate
, typename argument_type
>
178 : public std::unary_function
<argument_type
, bool>
185 unary_negate(const _Predicate
& __x
) : _M_pred(__x
) { }
188 operator()(const argument_type
& __x
)
189 { return !_M_pred(__x
); }
192 /** @brief Similar to std::binder1st,
193 * but giving the argument types explicitly. */
194 template<typename _Operation
, typename first_argument_type
,
195 typename second_argument_type
, typename result_type
>
197 : public std::unary_function
<second_argument_type
, result_type
>
201 first_argument_type value
;
204 binder1st(const _Operation
& __x
,
205 const first_argument_type
& __y
)
206 : op(__x
), value(__y
) { }
209 operator()(const second_argument_type
& __x
)
210 { return op(value
, __x
); }
212 // _GLIBCXX_RESOLVE_LIB_DEFECTS
213 // 109. Missing binders for non-const sequence elements
215 operator()(second_argument_type
& __x
) const
216 { return op(value
, __x
); }
220 * @brief Similar to std::binder2nd, but giving the argument types
223 template<typename _Operation
, typename first_argument_type
,
224 typename second_argument_type
, typename result_type
>
226 : public std::unary_function
<first_argument_type
, result_type
>
230 second_argument_type value
;
233 binder2nd(const _Operation
& __x
,
234 const second_argument_type
& __y
)
235 : op(__x
), value(__y
) { }
238 operator()(const first_argument_type
& __x
) const
239 { return op(__x
, value
); }
241 // _GLIBCXX_RESOLVE_LIB_DEFECTS
242 // 109. Missing binders for non-const sequence elements
244 operator()(first_argument_type
& __x
)
245 { return op(__x
, value
); }
248 /** @brief Similar to std::equal_to, but allows two different types. */
249 template<typename T1
, typename T2
>
250 struct equal_to
: std::binary_function
<T1
, T2
, bool>
252 bool operator()(const T1
& t1
, const T2
& t2
) const
256 /** @brief Similar to std::less, but allows two different types. */
257 template<typename T1
, typename T2
>
258 struct less
: std::binary_function
<T1
, T2
, bool>
261 operator()(const T1
& t1
, const T2
& t2
) const
265 operator()(const T2
& t2
, const T1
& t1
) const
269 // Partial specialization for one type. Same as std::less.
270 template<typename _Tp
>
271 struct less
<_Tp
, _Tp
> : public std::binary_function
<_Tp
, _Tp
, bool>
274 operator()(const _Tp
& __x
, const _Tp
& __y
) const
275 { return __x
< __y
; }
279 /** @brief Similar to std::plus, but allows two different types. */
280 template<typename _Tp1
, typename _Tp2
>
281 struct plus
: public std::binary_function
<_Tp1
, _Tp2
, _Tp1
>
283 typedef __typeof__(*static_cast<_Tp1
*>(NULL
)
284 + *static_cast<_Tp2
*>(NULL
)) result
;
287 operator()(const _Tp1
& __x
, const _Tp2
& __y
) const
288 { return __x
+ __y
; }
291 // Partial specialization for one type. Same as std::plus.
292 template<typename _Tp
>
293 struct plus
<_Tp
, _Tp
> : public std::binary_function
<_Tp
, _Tp
, _Tp
>
295 typedef __typeof__(*static_cast<_Tp
*>(NULL
)
296 + *static_cast<_Tp
*>(NULL
)) result
;
299 operator()(const _Tp
& __x
, const _Tp
& __y
) const
300 { return __x
+ __y
; }
304 /** @brief Similar to std::multiplies, but allows two different types. */
305 template<typename _Tp1
, typename _Tp2
>
306 struct multiplies
: public std::binary_function
<_Tp1
, _Tp2
, _Tp1
>
308 typedef __typeof__(*static_cast<_Tp1
*>(NULL
)
309 * *static_cast<_Tp2
*>(NULL
)) result
;
312 operator()(const _Tp1
& __x
, const _Tp2
& __y
) const
313 { return __x
* __y
; }
316 // Partial specialization for one type. Same as std::multiplies.
317 template<typename _Tp
>
318 struct multiplies
<_Tp
, _Tp
> : public std::binary_function
<_Tp
, _Tp
, _Tp
>
320 typedef __typeof__(*static_cast<_Tp
*>(NULL
)
321 * *static_cast<_Tp
*>(NULL
)) result
;
324 operator()(const _Tp
& __x
, const _Tp
& __y
) const
325 { return __x
* __y
; }
329 template<typename T
, typename _DifferenceTp
>
330 class pseudo_sequence
;
332 /** @brief Iterator associated with __gnu_parallel::pseudo_sequence.
333 * If features the usual random-access iterator functionality.
334 * @param T Sequence value type.
335 * @param difference_type Sequence difference type.
337 template<typename T
, typename _DifferenceTp
>
338 class pseudo_sequence_iterator
341 typedef _DifferenceTp difference_type
;
344 typedef pseudo_sequence_iterator
<T
, _DifferenceTp
> type
;
350 pseudo_sequence_iterator(const T
& val
, difference_type pos
)
351 : val(val
), pos(pos
) { }
353 // Pre-increment operator.
361 // Post-increment operator.
364 { return type(pos
++); }
371 operator[](difference_type
) const
375 operator==(const type
& i2
)
376 { return pos
== i2
.pos
; }
379 operator!=(const type
& i2
)
380 { return pos
!= i2
.pos
; }
383 operator-(const type
& i2
)
384 { return pos
- i2
.pos
; }
387 /** @brief Sequence that conceptually consists of multiple copies of
389 * The copies are not stored explicitly, of course.
390 * @param T Sequence value type.
391 * @param difference_type Sequence difference type.
393 template<typename T
, typename _DifferenceTp
>
394 class pseudo_sequence
396 typedef pseudo_sequence
<T
, _DifferenceTp
> type
;
399 typedef _DifferenceTp difference_type
;
401 // Better case down to uint64, than up to _DifferenceTp.
402 typedef pseudo_sequence_iterator
<T
, uint64
> iterator
;
404 /** @brief Constructor.
405 * @param val Element of the sequence.
406 * @param count Number of (virtual) copies.
408 pseudo_sequence(const T
& val
, difference_type count
)
409 : val(val
), count(count
) { }
411 /** @brief Begin iterator. */
414 { return iterator(val
, 0); }
416 /** @brief End iterator. */
419 { return iterator(val
, count
); }
423 difference_type count
;
426 /** @brief Functor that does nothing */
427 template<typename _ValueTp
>
431 operator()(const _ValueTp
& v
) const { }
434 /** @brief Compute the median of three referenced elements,
435 according to @c comp.
436 * @param a First iterator.
437 * @param b Second iterator.
438 * @param c Third iterator.
439 * @param comp Comparator.
441 template<typename RandomAccessIterator
, typename Comparator
>
443 median_of_three_iterators(RandomAccessIterator a
, RandomAccessIterator b
,
444 RandomAccessIterator c
, Comparator
& comp
)
456 // Just swap a and b.
467 #define _GLIBCXX_PARALLEL_ASSERT(_Condition) __glibcxx_assert(_Condition)
469 } //namespace __gnu_parallel
471 #endif /* _GLIBCXX_PARALLEL_BASE_H */